This invention relates generally to fusion of polyolefin pipes and more particularly concerns facers used to prepare pipe ends for the fusion process.
Present facer technology provides hydraulic or electric rotating planar block facers and single point cutting tools. Known block facers typically carry one to six blades on opposite faces of the planar block. As they rotate they slowly remove shavings from the pipes to create parallel faces of the pipes to be joined, usually but not always in a plane the perpendicular to the longitudinal axis of the pipes. Typically, the shavings are 0.010″ to 0.030″ thick and continuous along the pipe circumference. They pose significant clean up and disposal problems.
The cutting speed of these facers is limited by the diameter of the block. The greater their diameter, the less 360° cut rotations they can make per minute. It is quite common that one inch of pipe length will be removed during the facing process. At 0.010″ to 0.030″ per rotation, facing time can be quite lengthy. This is of particular concern in pipe fusion applications because pipe heating and fusion times are generally held within established standards. Therefore, progress in fusion efficiency is substantially limited to reduction of handling or facing times.
Non-matching ovalities of the pipes to be joined make efficient achievement of matching surfaces very difficult for block facers. Known single point cutting tools simply do not consistently provide cut finished surfaces suitable for pipe fusion standards.
It is, therefore, an object of this invention to provide a pipe facer that can operate at higher cutting speeds than known pipe facers. It is also an object of this invention to provide a pipe facer that is more likely to properly face pipes having non-matching ovalities than known pipe facers. A further object of this invention is to provide a pipe facer that affords greater time efficiency and quality consistency than known pipe facers. Another object of this invention is to provide a pipe facer that converts removed pipe material into a form easier to collect and dispose of than known pipe facers.